Are millennials poor tippers because they don't like the practice of tipping, or are they just trying to conserve their limited cash?

It's hard to draw any hard conclusions from a new survey from CreditCards.com that paints millennials – America's largest demographic, often dismissed by older folks as the Entitled Generation – as the "worst tippers in the U.S." According to the survey, a weighted study of 1,000 interviews, 10 percent of millennials routinely stiff their servers at restaurants.

Compare that figure with the percentage of Gen Xers and baby boomers who admitted stiffing the wait staff: 1.8 percent and 4.4 percent, respectively. The highest percentage of baby boomers (6.1 percent) who stiffed servers was found in the 64-72 age group, some of whom presumably live on fixed incomes and have to watch every cent.

Millennials are also more likely to select the lowest percentage when presented with tipping options at fast-casual restaurants or on an Uber app, according to the survey. Fourteen percent of millennials will pick the cheapest tip option, compared to 9.3 percent of Gen Xers and 4.8 percent of boomers.

On the surface, the survey would seem to offer more data that older Americans can use to feel superior to millennials, the generation they have derided as lazy, narcissistic and prone to communicating with their thumbs.

But there's something else to consider among the CreditCards.com data: More millennials than any other generation say they would prefer to eliminate tipping, a practice that has increasingly come under assault in America, including in Washington, where voters will decide Tuesday whether to gradually eliminate the tipped minimum wage. Nearly 27 percent of millennials would prefer to dine in restaurants with higher prices and no tipping, compared to 25 percent of Gen Xers and 13.5 percent of boomers.

"Older respondents tended to like tipping more, and its alternatives less, than did younger respondents," wrote Michael Lynn, a professor at the Cornell University School of Hotel Administration who researches tipping. The observation was part of Lynn's 2017 report, "Should U.S. Restaurants Abandon Tipping? A Review of the Issues and Evidence."

Contacted by email, Lynn agreed that younger diners tend to prefer no-tipping models more than older generations. "So this may explain their lower liking of tipping," Lynn wrote. "Perhaps they are more attentive to and affected by the recent social and media campaigns against tipping."

Another factor to consider about the CreditCards.com survey: The respondents were simply asked about their tipping behaviors at a "restaurant," without stipulating whether it was a full-service establishment or a fast-casual operation. Millennials tend to prefer dining experiences that are quick, customizable, communal and cheap, all the hallmarks of fast-casual dining. Tipping at such counter-service restaurants is not required, or at least not as much as at full-service restaurants where the wait staff often lives off tips.

Finally, millennials are still in their early wage-earning years, averaging about $35,000 per year. As Lynn noted via email, at least one study has shown that "tipping increases with income." In other words, once millennials make more money, they may be more willing to share the wealth with servers.